JP5450143B2 - Hot water system - Google Patents

Description

  The present invention relates to a hot water supply system in which an instantaneous heating type combustion water heater is connected in series downstream of a hot water storage tank for storing heated hot water.

  2. Description of the Related Art Conventionally, there is known a hot water supply system in which an instantaneous heating type combustion water heater is connected in series downstream of a hot water storage tank for storing heated hot water (see, for example, Patent Document 1). In this way, by connecting the hot water storage tank and the combustion water heater in series, even when the hot water storage tank runs out, the hot water supply at the target hot water temperature can be continued by operating the combustion water heater. It can be carried out.

  Further, in the conventional hot water supply system, a hot water pipe is connected to a hot water outlet pipe for extracting hot water from a hot water storage tank, and hot water and water are mixed by a mixing control valve provided as a mixing ratio changing means. At this time, mixing temperature control is performed to adjust the temperature of the hot water so that the temperature detected by the mixing temperature sensor provided downstream of the mixing control valve becomes the desired hot water supply temperature.

JP-A-10-196983

  However, in the configuration of the conventional hot water supply system described above, the hot water distribution path from the hot water storage tank to the end of the hot water discharge pipe via the combustion hot water supply device becomes long. For this reason, not only does the pressure loss in the distribution channel increase and a sufficient hot water flow rate is not obtained, but the hot water discharged from the hot water storage tank when the combustion of the combustion water heater is stopped is dissipated when passing through the combustion water heater. This has the disadvantage of lowering the temperature of the hot water.

  Therefore, it is conceivable to provide a bypass pipe that bypasses the combustion water heater and communicates the hot water discharge pipe on the upstream side and the downstream side of the combustion water heater. When a bypass pipe is provided in the conventional hot water supply system, the start of the bypass pipe is connected to a hot water pipe located between the combustion hot water heater and the mixing temperature sensor downstream of the mixing control valve, and the outlet side of the combustion hot water heater is connected. The end of the bypass pipe is connected to the hot water pipe located between the hot water tap and the hot water tap.

  Further, a bypass valve is provided in the bypass pipe. In this way, when the hot water storage tank is not out of water, the bypass valve is opened, and the hot water from the hot water storage tank is circulated to the bypass pipe to form a hot water circulation route that does not pass through the combustion water heater. It is possible to avoid pressure loss and heat dissipation of hot water caused by circulating through the combustion water heater. In addition, when the hot water storage tank runs out, the bypass valve is closed and hot water is circulated from the hot water storage tank to the combustion hot water heater to control the heating temperature by the combustion hot water heater, so that hot water at a desired temperature is obtained. Can be obtained.

  By the way, in order to accurately supply hot water at a desired temperature by performing mixing temperature control, all the components used for mixing temperature control such as the mixing control valve and the mixing temperature sensor are operated normally. It must be in a state.

  However, if any of the parts used in the mixed temperature control is out of order, even if trying to supply hot water through the bypass pipe, accurate mixed temperature control cannot be performed, so hot water at a desired temperature cannot be supplied. .

  In view of the above points, an object of the present invention is to provide a hot water supply system that can supply hot water at a desired temperature even when components used for mixed temperature control are broken.

The hot water supply system of the present invention includes a hot water storage tank, tank heating means for heating the hot water in the hot water storage tank, a hot water storage temperature sensor for detecting the temperature of the hot water in the hot water storage tank, and the hot water storage tank connected to the hot water storage tank. A hot water pipe for deriving hot water in the hot water storage tank, a hot water supply pipe connected to the hot water storage tank and the hot water discharge pipe, hot water supplied from the hot water storage tank to the hot water discharge pipe, and supplied from the water supply pipe to the hot water discharge pipe The mixing ratio changing means for changing the mixing ratio with water, and the hot water that is provided in the middle of the hot water pipe at the downstream side of the connection point between the hot water pipe and the water supply pipe, a combustion water heater for heating via a heat exchanger, made to communicate with an upstream side and a downstream side of the combustion water heater of the hot water pipe, a small hot water pressure loss flowing through said output hot water pipe from the combustion water heater hot water bypass pipe to A bypass valve that opens and closes the hot water bypass pipe, a mixed temperature sensor that detects the temperature of hot water mixed by the mixing ratio changing means, and a hot water heater temperature sensor that detects the temperature of hot water heated by the heat exchanger And hot water supply temperature setting means for setting the target hot water supply temperature, and when the detected temperature of the hot water storage temperature sensor is higher than the hot water outage determination temperature set according to the target hot water supply temperature during hot water supply, the hot water supply pipe is circulated. taking into account the hot water in the pressure loss to an open state of the bypass valve, so that the detection temperature before Symbol mixing temperature sensor becomes the target hot-water supply temperature, mixing temperature for adjusting the mixing ratio by the mixing ratio changing means If the detected temperature of the hot water storage temperature sensor is equal to or lower than the hot water judgment temperature during hot water supply, the bypass valve is closed and the hot water heater temperature sensor is detected. Temperature regulation control means for performing heating temperature regulation control for heating by the combustion water heater so that the temperature becomes the target hot water temperature, and the temperature regulation control means includes the mixing ratio changing means, the mixing temperature When at least one of the sensor, the hot water storage temperature sensor, and the tank heating means fails, the bypass valve is closed to control the mixed temperature in consideration of hot water pressure loss. The heating temperature control is executed at the expense of control.

  In the hot water supply system of the present invention, as described in the embodiment, when hot water runs out in the hot water storage tank, the hot water in the hot water storage tank is circulated to the combustion hot water heater and heated by the heating temperature control, thereby heating the target hot water supply temperature. The hot water can be produced.

  If the hot water tank does not run out, open the bypass valve to supply hot water from the hot water tank through the hot water bypass pipe without circulating the hot water from the hot water tank to the combustion water heater. At this time, mixed temperature control is performed to generate hot water having a target hot water temperature. Thereby, the pressure loss and heat dissipation of hot water by circulating through the combustion hot water heater can be avoided, and hot water having a temperature set by the hot water supply temperature setting means can be obtained.

  When performing the mixing temperature control, if a failure occurs in at least one of the mixing ratio changing unit, the mixing temperature sensor, the hot water storage temperature sensor, and the tank heating unit, the mixing temperature control is performed. It becomes difficult to generate hot water at the target hot water supply temperature by the control. Therefore, the temperature control means performs heating temperature control with the bypass valve closed when the failure occurs. By doing so, the hot water in the hot water storage tank is guided to the combustion water heater without passing through the hot water bypass pipe, and the heating temperature control is performed using the water heater temperature sensor provided in the combustion water heater. Therefore, hot water having a target hot water temperature can be generated by the heating temperature control of the combustion water heater, and hot water having a desired temperature set by the hot water temperature setting means can be used even when the mixed temperature control cannot be performed normally. Can be obtained.

  Further, in the hot water supply system of the present invention, the mixing ratio changing means is provided between a connection portion between the hot water storage pipe and the hot water storage tank and a connection portion between the water supply pipe and changes the amount of hot water discharged from the hot water storage tank. A hot water variable valve, and a water volume variable valve that is provided between a connection portion of the hot water storage tank in the water supply pipe and a connection portion of the hot water discharge pipe and changes the amount of water flowing from the water supply pipe to the hot water discharge pipe, The temperature control means, when a failure occurs in the mixing temperature sensor, closes the bypass valve, closes the hot water variable valve, closes the water variable valve, and opens the water variable valve. Control is executed.

  When a hot water of a sufficient amount is stored in the hot water storage tank, when the mixed temperature sensor does not function normally when the bypass valve is opened and hot water is supplied through the hot water bypass pipe, Even if you try to adjust the mixing ratio of hot water and water by the opening of the hot water variable valve and the water variable valve, the opening of the hot water variable valve becomes extremely large and the hot water in the hot water tank is mixed with water It is possible that the hot water is supplied without any change. Therefore, in the hot water supply system of the present invention, when a failure occurs in the mixed temperature sensor, the hot water variable valve is closed and the water variable valve is opened. By this, by heating the water supplied from the water supply pipe by the combustion water heater without letting out hot water from the hot water storage tank, hot water having the target hot water temperature by heating temperature control can be generated. Hot water having a desired temperature set by the hot water supply temperature setting means can be obtained.

The block diagram of the hot-water supply system in embodiment of this invention. The flowchart which shows the action | operation in the hot-water supply system shown in FIG.

  Embodiments of the present invention will be described with reference to the drawings. With reference to FIG. 1, the hot water supply system of the present embodiment is configured by an instantaneous heating combustion water heater 10, a tank unit 30, and a heat pump unit 60.

  The heat pump unit 60 (corresponding to the tank heating means of the present invention) includes a heat pump 70 configured by connecting a compressor 71, a condenser 72, a decompressor 73, and an evaporator 74 through a refrigerant circulation path 75. ing. The condenser 72 is connected to a tank circulation path 64 connected to the upper and lower parts of the hot water storage tank 31, and exchanges heat between the refrigerant in the refrigerant circulation path 75 and the hot water in the tank circulation path 64, whereby the tank circulation path. The hot water in 64 is heated.

  The tank circulation path 64 includes a circulation pump 65 for circulating the hot water stored in the hot water storage tank 31 into the tank circulation path 64, and a forward thermistor for detecting the temperature of the hot water supplied from the condenser 72 to the hot water storage tank 31. 66 and a return thermistor 41 for detecting the temperature of the hot water supplied from the hot water storage tank 31 to the condenser 72 are provided.

  Then, a temperature detection signal from the forward thermistor 66 is input to the heat pump controller 80 constituted by a microcomputer or the like. Further, the operation of the heat pump 70 and the circulation pump 65 is controlled by a control signal output from the heat pump controller 80.

  The heat pump controller 80 is communicably connected to the tank controller 50, and performs a boiling operation when receiving a hot water storage instruction signal from the tank controller 50. That is, using the boiling set temperature transmitted from the tank controller 50, the circulating pump 65 and the heat pump 70 are operated based on the detected temperature of the forward thermistor 66 and the detected temperature of the return thermistor 41, and hot water in the hot water storage tank 31. Is heated to the set boiling temperature.

  The tank unit 30 bypasses the hot water storage tank 31, the hot water pipe 2 whose start is connected to the upper part of the hot water storage tank 31, the water supply pipe 1 connected to the lower part of the hot water storage tank 31 and the hot water discharge pipe 2, and the combustion water heater 10. The hot water discharge pipe 2 is provided with a hot water supply bypass pipe 37 that communicates the upstream side and the downstream side of the combustion water heater 10. Further, a currant 3 is provided at the end of the hot water discharge pipe 2.

  The tank unit 30 includes a return thermistor 41 that detects the temperature of hot water supplied from the hot water storage tank 31 to the heat pump unit 60, a hot water storage thermistor 32 that detects the temperature of the upper layer portion of the hot water stored in the hot water storage tank 31, and an outlet pipe 2, a hot water thermistor 33 provided on the upstream side of the connection point X with the water supply pipe 1, a tank flow rate sensor 46 for detecting the amount of hot water discharged from the hot water storage tank 31, and an incoming water flow rate for detecting the water flow rate of the water supply pipe 1. A sensor 43, a water thermistor 44 provided in the water supply pipe 1, a hot water variable valve 34 that changes the amount of hot water discharged from the hot water storage tank 31 to the hot water discharge pipe 2, and an amount of water that changes the amount of water flowing from the water supply pipe 1 toward the hot water discharge pipe 2. Provided between the variable valve 35, the pressure reducing valve 40 with a check valve provided in the water supply pipe 1, and the connection point X between the hot water pipe 2 and the water supply pipe 1 and the hot water bypass pipe 37. A mixing thermistor 36, a bypass valve 38 for opening and closing the hot water bypass pipe 37, and a hot water supply outlet thermistor 39 for detecting the temperature of hot water supplied downstream of the connection point Y between the hot water bypass pipe 37 and the hot water pipe 2 are provided. ing.

  The hot water variable valve 34 and the water variable valve 35 constitute the mixing ratio changing means of the present invention, and the mixing thermistor 36 and the hot water outlet thermistor 39 constitute the mixing temperature sensor of the present invention.

  A temperature detection signal from a hot water storage thermistor 32, a hot water thermistor 33, an incoming water thermistor 44, a mixed thermistor 36, a hot water supply outlet thermistor 39, and a return thermistor 41, and an incoming water flow rate sensor 43 are added to a tank controller 50 constituted by a microcomputer or the like. A detection signal of the water flow rate of the water supply pipe 1 is input. Further, the operation of the hot water variable valve 34, the water variable valve 35, and the bypass valve 38 is controlled by a control signal output from the tank controller 50.

  The tank controller 50 monitors the detected temperatures of the return thermistor 41 and the hot water storage thermistor 32 and transmits the hot water storage heating instruction signal described above to the heat pump controller 80 based on the detected temperatures. Thereby, the hot water in the hot water storage tank 31 is heated to the boiling temperature set by the heat pump unit 60.

  In the tank controller 50, a desired hot water supply temperature (temperature of hot water supplied from the currant 3) and bath temperature (the hot water supplied to the bathtub via a hot-water pipe 18, which will be described later), are supplied to the tank controller 50. A temperature switch (not shown) for setting a temperature), a general hot water supply mode (a mode in which a hot water filling valve 19 described later is closed and hot water is supplied from the currant 3), and a hot water filling mode (a hot water filling valve 19 is turned on). A remote controller 51 having a mode changeover switch (not shown) or the like for switching between a mode in which the valve is opened and hot water is supplied from the hot water filling pipe 18 to the bathtub is connected.

  The hot water discharge pipe 2 is connected to the upper part of the hot water storage tank 31, and the water supply pipe 1 is connected to the lower part of the hot water storage tank 31. Therefore, in the hot water storage tank 31, a hot water layer is formed at the top and a water layer is formed at the bottom (temperature stratification). When the hot water is discharged from the hot water storage tank 31, the upper hot water layer is reduced accordingly.

  Then, the hot water storage thermistor 32 detects the temperature of the upper layer portion of the hot water storage tank 31, and the detected temperature is the target hot water temperature set by the remote controller 51 (the hot water supply set temperature set by the remote controller 51 in the general hot water supply mode, When the temperature is equal to or lower than the bath set temperature set by the remote controller 51, the hot water runs out.

  The tank controller 50 causes the detected temperature of the mixed thermistor 36 or the hot water supply outlet thermistor 39 to become the target temperature when the incoming water flow rate sensor 43 detects water flow exceeding a predetermined lower limit flow rate in a state where hot water has not run out. In addition, mixed temperature control for controlling the opening degree of the hot water variable valve 34 and the water variable valve 35 is performed. At this time, the tank controller 50 opens the bypass valve 38 in the general hot water supply mode, and closes the bypass valve 38 in the hot water filling mode.

  On the other hand, when a water flow exceeding the lower limit water amount is detected by the incoming water flow sensor 43 in a state where the hot water has run out, the tank controller 50 closes the bypass valve 38 and removes the hot water from the hot water storage tank 31 and the water supply pipe 1. All the hot water is supplied to the combustion water heater 10. In this case, the heating temperature adjustment control is executed in the combustion water heater 10.

  Further, the tank controller 50 electrically performs abnormal operations of the hot water variable valve 34, the water variable valve 35, the mixed thermistor 36, the hot water supply outlet thermistor 39, and the hot water storage thermistor 32, which are load parts for performing the mixed temperature control. A function (load component failure detection means) that detects and automatically detects a failure is provided. Moreover, the tank controller 50 can grasp | ascertain the presence or absence of the failure as the heat pump unit 60 as one of the load parts. That is, the heat pump controller 80 has a function of detecting an abnormality of the heat pump 70 or the like (a state where a normal boiling operation is not performed due to a failure of each component or the like), and an abnormality of the heat pump 70 or the like is detected. At this time, an error signal is transmitted to the tank controller 50. The tank controller 50 grasps the failure of the heat pump unit 60 by receiving an error signal from the heat pump controller 80. The operation of the hot water supply system according to the present invention when the tank controller 50 detects the failure will be described later.

  The combustion hot water heater 10 bypasses the heat exchanger 11 provided in the middle of the hot water pipe 2, the burner 12 that heats the heat exchanger 11, and the heat exchanger 11, and connects the hot water pipe 2 to the heat exchanger 11. A hot water supply bypass pipe 13 communicating with the upstream side and the downstream side, and a hot water filling pipe 18 connecting the bathtub (not shown) and the hot water supply pipe 2 on the downstream side of the connection point Z between the hot water supply pipe 2 and the hot water supply bypass pipe 13 are provided. ing.

  The hot water supply pipe 2 is supplied to a bypass servo 14 that changes a distribution ratio between the flow rate of hot water supplied to the heat exchanger 11 side and the flow rate of hot water supplied to the hot water supply bypass pipe 13 side, and the combustion hot water supply 10. A water volume servo 15 for adjusting the flow rate of hot water, a hot water flow rate sensor 21 for detecting the flow rate of hot water supplied to the heat exchanger 11 and the hot water supply bypass pipe 13, and a connection point Z between the hot water discharge pipe 2 and the hot water supply bypass pipe 13. A hot water heater thermistor 16 for detecting the temperature of the hot water supplied to the downstream side of the gas and a check valve 17 are provided. The hot water filling pipe 18 is provided with a hot water filling flow rate sensor 22 for detecting the flow rate of the hot water filling pipe 18 and a hot water filling valve 19 for opening and closing the hot water filling pipe 18.

  A temperature detection signal from the water heater thermistor 16, a water flow rate detection signal from the water heater flow sensor 21, and a water flow rate detection signal from the hot water flow rate sensor 22 are supplied to the hot water controller 20 constituted by a microcomputer or the like. Are entered. Further, the operation of the bypass servo 14, the water amount servo 15, the burner 12, and the hot water filling valve 19 is controlled by a control signal output from the hot water supply controller 20.

  The hot water supply controller 20 is communicably connected to the tank controller 50 and enters a heating permission state when receiving a signal for instructing heating from the tank controller 50. The heating temperature for controlling the combustion amount of the burner 12 so that the detected temperature of the hot water heater thermistor 16 becomes the target hot water temperature when water flow of a predetermined lower limit flow rate is detected by the hot water heater flow rate sensor 21. Execute adjustment control. Further, when a signal for instructing heating is received from the tank controller 50, the heating is prohibited and execution of the heating temperature control is prohibited.

  In addition, the hot water supply controller 20 opens the hot water filling valve 19 when the hot water filling operation for supplying a predetermined amount of hot water to a bathtub (not shown) (hot water filling mode) is performed by the hot water filling flow rate sensor 22. Accumulate the amount of hot water supplied to the detected bathtub. When the cumulative amount of hot water supplied to the bathtub reaches the predetermined amount, the hot water filling valve 19 is closed to end the hot water filling operation.

  The tank controller 50 and the hot water supply controller 20 constitute temperature control means in the present invention.

  In the present embodiment, the hot water heating function and the bath reheating function are omitted. However, when a hot water supply system having a hot water heating function is constructed, for example, although not shown, heat exchange for heating is performed in the combustion water heater 10. A heater and a heating burner for heating the heater may be additionally provided, and the forward and return pipes of the heating terminal may be connected to the outlet pipe and the inlet pipe of the heating heat exchanger, respectively. Furthermore, if a hot water storage tank 31 is provided with a heating heat exchange circuit and heat exchange is performed with a heating return pipe via a liquid-liquid heat exchanger, heat can be advantageously supplied to the hot water in the hot water storage tank 31. Furthermore, a bath replenishment function can be obtained by exchanging heat with the bath circulation path via a liquid-liquid heat exchanger in the heating forward pipe.

  Next, the operation of the tank controller 50 corresponding to the gist of the present invention will be described. When the power of the tank unit 30 is turned on in STEP 1 of FIG. 2, the process proceeds to STEP 2 and the tank controller 50 fully closes the hot water variable valve 34 and fully opens the water variable valve 35. Then, the tank controller 50 opens the bypass valve 38 in subsequent STEP3.

  In the next STEP 4, the tank controller 50 waits for the water flow rate sensor 43 to detect water flow exceeding the lower limit flow rate. And when it becomes a water flow state, it progresses to STEP5 from STEP4.

  In STEP5, if the tank controller 50 has detected the failure of the load component for the mixed temperature control, the process branches to STEP11, and if the failure of the load component has not been detected, the process proceeds to STEP6.

  When the power is turned on in STEP 1, the tank controller 50 starts monitoring the operation of the load component, and proceeds to STEP 11 from STEP 5 if a failure is detected in any one of the load components. The load components monitored by the tank controller 50 are for performing mixed temperature control. In the present embodiment, the hot water amount variable valve 34, the water amount variable valve 35, the mixed thermistor 36, the hot water supply outlet thermistor 39, and the hot water storage This is the thermistor 32. For example, the tank controller 50 detects a failure with respect to the mixing thermistor 36, the hot water supply outlet thermistor 39, and the hot water storage thermistor 32 when the detected current (or voltage) is an abnormal value (over or under compared with the normal temperature detection). A fault is detected for the hot water variable valve 34 and the water variable valve 35 when the control current (or voltage) is an abnormal value (excessive or excessive as compared with normal operation).

  Further, as described above, the tank controller 50 also monitors the heat pump unit 60 as a load component. In this case, when the tank controller 50 receives an error signal from the heat pump controller 80, it is considered that the heat pump unit 60 has failed.

  In STEP 6, the tank controller 50 determines whether or not the hot water storage thermistor 32 is in a hot water out condition where the detected temperature is equal to or lower than the target hot water supply temperature. When the hot water is out, the process branches to STEP 13, and when the hot water is not out, the process proceeds to STEP7.

  STEP7 to STEP9 are processes for executing the mixing temperature control. That is, the tank controller 50 opens the bypass valve 38 in STEP 7 and transmits a signal instructing prohibition of heating to the hot water supply controller 20 in STEP 8. In subsequent STEP 9, the tank controller 50 adjusts the opening of the hot water variable valve 34 and the water variable valve 35 so that the temperature of the hot water supplied from the currant 3 basically becomes the target hot water temperature. (Mixing temperature control).

  And the tank controller 50 repeats and executes the loop which consists of STEP5-STEP10 until it will be in the water stop state by which the water flow more than a minimum flow volume is not detected by STEP10 at STEP10.

  Here, the processing in the case where the process proceeds to STEP 13 because the detected temperature of the hot water storage thermistor 32 is equal to or lower than the target hot water supply temperature in STEP 6 will be described first. STEP13 to STEP15 are processes for executing the heating temperature control. The tank controller 50 closes the bypass valve 38 in STEP 13, and transmits a signal instructing heating permission to the hot water supply controller 20 in STEP 14. In subsequent STEP 15, the hot water controller 20 that has received the heating permission signal from the tank controller 50 controls the combustion amount of the burner 12 so that the detected temperature of the hot water heater thermistor 16 becomes the target hot water temperature on the combustion hot water heater 10 side. (Heating temperature control)

  After that, in STEP 10, the tank controller 50 stops the operation of the hot water variable valve 34 and the water variable valve 35 when the water flow rate sensor 43 detects that the water flow exceeding the lower limit flow rate has not been detected. The opening is maintained at, and the process returns to STEP5.

  Next, the processing when the tank controller 50 proceeds to STEP 11 because the tank controller 50 detects a failure of the load component in STEP 5 will be described. In STEP 11, the tank controller 50 determines whether the load component that has detected the failure is the mixed thermistor 36 or the hot water supply outlet thermistor 39. If the failure is other than the mixing thermistor 36 or the hot water supply outlet thermistor 39, the process proceeds to the above-described STEP13.

  On the other hand, when a failure of the mixing thermistor 36 or the hot water supply outlet thermistor 39 is detected in STEP 11, the tank controller 50 fully closes the hot water variable valve 34 and fully opens the water variable valve 35 in STEP 12. To step 13 described above.

  In STEP 12, the hot water variable valve 34 is fully closed and the water variable valve 35 is fully opened, so that the hot water supply from the hot water storage tank 31 is stopped even if the hot water storage tank 31 has not run out of water. Thus, only water is supplied to the hot water discharge pipe 2. Then, by bypassing the bypass valve 38 in STEP 13, only water is supplied from the water supply pipe 1 to the combustion water heater 10, and the heating temperature control is executed by STEP 14 and STEP 15 that follow.

  According to this, the opening degree adjustment of the hot water variable valve 34 and the water variable valve 35 becomes inaccurate due to the failure of the mixing thermistor 36 or the hot water supply outlet thermistor 39, for example, hot hot water from the hot water storage tank 31 is The situation where it is supplied without being mixed with the water from the water supply pipe 1 can be avoided.

  Further, even if there is a failure other than the mixing thermistor 36 or the hot water supply outlet thermistor 39, the process proceeds to STEP13, and the heating temperature control is executed by STEP14 and STEP15. Even if the adjustment becomes inaccurate, hot water at the target hot water temperature can be obtained by heating the combustion water heater 10.

  Even if the failure of the load component by the tank controller 50 is detected in STEP 5 and the processing of STEP 11 to STEP 15 is repeatedly executed, the failure of the load component by the tank controller 50 is not detected during the repeated execution. Advances from STEP5 to STEP6, and processing from STEP6 to STEP10 is performed.

Although not shown, STEP 11 and STEP 12 may not be provided, and if the tank controller 50 detects a failure of the load component in STEP 5, the process may proceed to STEP 13. In this case, since the mixing temperature control is in a state that can not be performed properly, the bypass valve 38 was closed valve by STEP 13, since performing the heat temperature control in the combustion water heater 10 side by STEP14 and STEP 15, the target hot-water supply Temperature hot water can be obtained.

  In the present embodiment, the hot water supply system using the heat pump 70 as the means for heating the hot water in the hot water storage tank 31 is shown, but other tank heating means such as a solar system may be adopted. In this case, the tank controller 50 may be configured so that the failure of other tank heating means such as a solar system can be grasped by communication.

  DESCRIPTION OF SYMBOLS 1 ... Water supply pipe, 2 ... Hot water pipe, 10 ... Combustion water heater, 11 ... Heat exchanger, 12 ... Burner, 16 ... Hot water heater thermistor (hot water heater temperature sensor), 31 ... Hot water storage tank, 32 ... Hot water storage thermistor (hot water storage temperature) Sensor), 34 ... Hot water amount variable valve (mixing ratio changing means), 35 ... Water amount variable valve (mixing ratio changing means), 36 ... Mixing thermistor (mixing temperature sensor), 37 ... Hot water bypass pipe, 38 ... Bypass valve, 39 ... Hot water supply outlet thermistor (mixing temperature sensor), 50 ... tank controller (temperature control means), 51 ... remote control (hot water temperature setting means), 60 ... heat pump unit (tank heating means).

Claims (2)

A hot water storage tank,
Tank heating means for heating hot water in the hot water storage tank;
A hot water storage temperature sensor for detecting the temperature of hot water in the hot water storage tank;
A hot water outlet pipe connected to the hot water storage tank and leading out hot water in the hot water storage tank;
A water supply pipe connected to the hot water storage tank and the hot water discharge pipe;
A mixing ratio changing means for changing a mixing ratio between hot water supplied from the hot water storage tank to the hot water discharge pipe and water supplied from the water supply pipe to the hot water discharge pipe;
A combustion water heater that is provided in the middle of the hot water pipe at a downstream side of a connection portion between the hot water pipe and the water supply pipe, and heats hot water flowing through the hot water pipe through a heat exchanger with a burner;
And communicates an upstream side and a downstream side of the combustion water heater of the hot water pipe, a hot water bypass pipe and a small hot water pressure loss flowing through said output hot water pipe from the combustion water heater,
A bypass valve for opening and closing the hot water bypass pipe;
A mixing temperature sensor for detecting the temperature of the hot and cold water mixed by the mixing ratio changing means;
A water heater temperature sensor for detecting the temperature of hot water heated by the heat exchanger;
Hot water temperature setting means for setting a target hot water temperature;
When the temperature detected by the hot water storage temperature sensor during hot water supply is higher than the hot water outage determination temperature set in accordance with the target hot water supply temperature, the bypass valve is opened in consideration of the pressure loss of hot water flowing through the hot water pipe. a state, before SL as the detected temperature of the mixed temperature sensor becomes the target hot-water supply temperature, the by mixing ratio changing means performs the mixing temperature adjustment control for adjusting the mixing ratio, the detection of the hot water storage temperature sensor when the hot water supply When the temperature is equal to or lower than the hot water run-off temperature, the bypass valve is closed, and the heating temperature control is performed so that the combustion water heater performs heating so that the temperature detected by the water heater temperature sensor becomes the target hot water temperature. Temperature control means for executing the control,
The temperature adjustment control means closes the bypass valve when a failure occurs in at least one of the mixing ratio changing means, the mixing temperature sensor, the hot water storage temperature sensor, and the tank heating means. A hot water supply system that performs the heating temperature adjustment control by sacrificing the mixing temperature adjustment control in consideration of the pressure loss of the hot water. The mixing ratio changing means is provided between the connecting portion of the hot water storage pipe with the hot water storage tank and the connecting portion of the water supply pipe, and changes the amount of hot water discharged from the hot water storage tank. A water amount variable valve provided between a connecting portion with the hot water storage tank and a connecting portion between the hot water pipe and changing the amount of water from the water supply pipe toward the hot water pipe;
The temperature control means sets the bypass valve to a closed state, the hot water variable valve to a closed state, and the water variable valve to an open state when a failure occurs in the mixed temperature sensor, and sets the heating temperature. The hot water supply system according to claim 1, wherein adjustment control is executed.

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